Koine

Definitions

from The American Heritage® Dictionary of the English Language, 4th Edition

n. A dialect of Greek that developed primarily from Attic and became the common language of the Hellenistic world, from which later stages of Greek are descended.

n. A lingua franca.

n. A regional dialect or language that becomes the standard language over a wider area, losing its most extreme local features.

from Wiktionary, Creative Commons Attribution/Share-Alike License

proper n. The "common" Greek language that developed and flourished between 300 BCE and 300 CE (the time of the Roman Empire), and from which Modern Greek descended. It was based on the Attic and Ionian dialects of Ancient Greek.

Embedded in Koine Greek, and preserved in Latin translations of the Bible, a few Hebrew terms were widely employed in Old English, such as amen and alleluia, Hebrew for “so be it” and “praise Yah,” more often rendered “verily” and “praise the Lord.”

I think that the Magi – all of them – have to be Persian, because that word has extremely strong connotations (adopted from Persian by Koine and Latin), specifically the regarding the Magians, ie. the Zoroastrian priests.